In order to reduce the mounting complexity during the assembly of a motor vehicle engine and to reduce logistics and storage costs during engine assembly, modules which are already finally assembled are supplied to the assembly line of the car manufacturers by the suppliers. Modules of this type consist, for example, of a cylinder head cover and a camshaft which is mounted therein. During the assembly of the engine, this module can be handled more simply than the individual constituent parts and can be mounted on the cylinder head of the engine.
EP 1155770 B1 has disclosed an assembly method for a module which comprises a cylinder head cover and a camshaft which is mounted therein. In the assembly method which is described, a cylinder head cover is provided with leadthroughs which are penetrated by the shaft, the subsequent camshaft. The components to be fastened on the shaft, such as cams, have to be arranged in specific seats in such a way that they are situated precisely in the required angular orientation and the required axial position, in accordance with their arrangement on the finally constructed camshaft. After the components and the cylinder head cover are oriented with respect to one another, the support shaft is pushed through the leadthroughs. The cams are fastened on the shaft by means of a press joint. In order to produce this press joint, various possibilities are specified in EP 1155770 B1. According to one of these possibilities, the press joint is produced by the shaft being pressed into the cams under the exertion of force.
It is a disadvantage of this method that the cams are pushed over the entire shaft and in the process damage the surface of the shaft with scratches and/or score marks. Damage of this type is very disadvantageous precisely in the region of the bearing points.
Another possibility disclosed in EP 1155770 B1 for producing the press joint consists in the shaft being widened in the region of the components by means of internal high pressure reshaping processes and the components being fastened in the process by means of a shrink fit. One disadvantage of this fastening process consists in no information being available about the press fit which is produced and therefore about the fastening of the cams on the shaft, by way of which information the quality of the connection between the cam and the shaft can be assessed. Reliable series production is therefore possible only with difficulty. An insufficient press fit or a damaged cam therefore initially remains unnoticed.
Moreover, the method which is known from EP 1155770 B1 is complicated and associated with high costs, since the components to be fastened on the shaft already have to be positioned and oriented before being pushed onto the shaft in precisely the same way as they are to be arranged on the subsequent camshaft. In order to achieve this, specific holding elements are required, into which the components can be inserted and can be held therein in an angularly and positionally correct manner. The production of these holding elements is complicated and expensive. Moreover, different holding elements are required for different camshafts, since the angular orientation of the cams is, for example, dependent on the engine (for example, 2-cylinder or 4-cylinder), as a result of which this method is very in-flexible.